This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. For this Core, one prime function is to provide high level flow cytometric capabilities to analyze stem and progenitor cell populations (and their progeny) based on immunological, genetic, physical, and/or metabolic properties. These capabilities are of importance in working with rare pluripotent stem and progenitor populations, but also find excellent application in cell and biomedical investigations at-large. Core B specifically is equipped with a Becton Dickinson FACS-Calibur flow cytometer that enables 4-color (immuno)staining plus forward and side scatter analyses. It's also coupled to dedicated workstations with high-end software for population analyses at the single-cell level (including apoptosis and cell cycle parameters). Flo-Jo, Win-List and related programs are also supported to facilitate publication-quality graphics of complex cytograms (via dedicated workstations). With the continuing success of our Center (and Institute), use of our flow cytometry system is increasing significantly. During present year-7, users also have begun to make increasing use of this Core's multi-well high-throughput fluorimetry / luminometry instrumentation (with a newly acquired modulus system plus injectors), as well as a versatile Vi-Cell cell analyzer.